import math
x1,y1,x2,y2=(float(x) for x in input().split())
print('{:.05f}'.format(math.sqrt((x2-x1)**2+(y2-y1)**2))) import math math float(x) for x in input().split() for x in input().split() x input().split() ().split () input split for x in input().split() float(x) float x x1,y1,x2,y2=(float(x) for x in input().split()) x1 (float(x) for x in input().split()) y1 x2 y2 print('{:.05f}'.format(math.sqrt((x2-x1)**2+(y2-y1)**2))) print '{:.05f}'.format(math.sqrt((x2-x1)**2+(y2-y1)**2)) '{:.05f}'.format '{:.05f}' format math.sqrt((x2-x1)**2+(y2-y1)**2) math.sqrt math sqrt (x2-x1)**2+(y2-y1)**2 (x2-x1)**2 x2-x1 x2 x1 2 (y2-y1)**2 y2-y1 y2 y1 2 x1,y1,x2,y2=(float(x) for x in input().split()) (float(x) for x in input().split()) x1 x2,y2=(float(x) for x in input().split()) (float(x) for x in input().split()) x2 y1,x2,y2=(float(x) for x in input().split()) (float(x) for x in input().split()) y1 y2=(float(x) for x in input().split()) (float(x) for x in input().split()) y2
import math
x1,y1,x2,y2=(float(x) for x in input().split())
print('{:.05f}'.format(math.sqrt((x2-x1)**2+(y2-y1)**2)))
